The invention relates to a process as well as to a device for breaking down or foaming starch or to a process and a device for producing a product or material, preferably a foam, by breaking down and/or foaming starch during extrusion.
A foam made of unmodified starch has already been proposed in particular for use as filling and packing material (DE-GM 92 12 899).
This foam, for which the most varied possible uses exist, has the advantage that it consists exclusively of an afterexpanding raw material and after use can also be disposed of without damage to the environment.